In U.S. Pat. No. 5,716,290, applicants introduced a putter having top spin facility afforded by an insert for a golf club head having an arcuate golf ball engaging surface.
Particularly, in the '290 patent, applicants disclosed in combination:
(a) a club head for a golf club, the club head having a front surface and a rear surface; and
(b) a member secured to the front surface of the club head and comprised of a material different from material constituting the club head, the member defining a front surface for hitting engagement with a golf ball, the member front surface having an arcuate configuration frontally of the club head front surface, the front surface of the club head adjacent the ends of the member having the same arcuate configuration as the member front surface.
By way of further introduction to the present invention, applicants noted golf club heads having inserts in the prior art as follows, as set forth in the '290 patent.
Another consideration of long-standing in the design of golf clubs is so-called "top spin" facility. Lawton U.S. Pat. No. 1,525,137 advised in 1925 of the value of imparting curvature to a putter ball engaging surface to impart "overspin" to the ball.
The following patents show various top spin surface arrangements: Barr U.S. Pat. No. 3,989,257; Thompson U.S. Pat. No. 4,162,074; Nebbia U.S. Pat. No. 4,902,015; Tucker U.S. Pat. No. 4,964,639; Garcia U.S. Pat. No. 5,303,923 and Sneed U.S. Pat. No. 5,382,019.
Limitation is seen in that all such top spin surfaces are constituted by the same material as the club head.
By way of further indication of prior art practices in the design of golf clubs, note is made of Clark et al. U.S. Pat. No. 4,253,667 and Tucker U.S. Pat. No. 4,964,639. Clark et al. advise of weighting practices, such as forming cavities in club heads and loading the cavities with shot held in place by a matrix. Tucker discloses application of a resilient member, such as a polyurethane rubber, to the front face of a putter to provide "feel" and protection.